摘要
本文评述了近年超塑性材料断裂研究理论进展。理论分析得出的一系列关系式可以反映这两个参数对塑性的贡献。其中 L-Z-B 关系式可以将经典理论和现代分析结合,描述了材料塑性和超塑性的基本规律。在众多限制超塑性变形能力的因素中,孔洞的影响可以通过综合了 m 值和孔洞长大速率两个参数(宏观参数和微观参数)的“超塑性断裂机构图”得以反映;当 m 值在变形中变化时,可以建立延伸率与最终 m 值之间的定量关系,这一关系又恰好与 G-A 的 m-ef 关系在形式上完全一致;各种缺陷(初始的或环境的)影响可以在理论分析中被反映,并且建立了它们之间的定量关系。
An overview was given on thy evolution of the theories of superplastic fracture.A series of relationship has been proposed,which reflects the contr- ibution of two material parameters to plasticity and superplasticity.L-Z-B,s relation which includes both Coasidere's classical criterion and G-A relation as special cases can be considered as a general expression for both plasticity and superplasticity.Among several other factors influencing superplastic frac- ture,the effect of cavity growth can be simply represented by the “superpl- astic fracture mechanism diagram”:for the variation of m during deformat- ion,a good approximate relation between the total elongation and the final m value was found by theoretical analysis;and various other defects can be introduced into the m-e relationship,and their relative importance is discu- ssed.
基金
国家教委优秀年轻教师基金资助
关键词
超塑性材料
断裂
superplastic fracture
cavity growth
supcrplastic fracturc mechanism
